1. Field of the Invention
The invention relates to a method and apparatus for generating or receiving a television signal comprising additional data, and to the television signal comprising the additional data.
2. Description of the Related Art
WO 94/28678, corresponding to U.S. Pat. No. 5,627,592 (Attorney's docket PHN 14,478) discloses an extended television signal comprising signalling bits for conveying control information to control an extended television signal decoder. As can be seen from FIG. 11 of WO 94/28678, the signalling bits contain a series of bits conveyed in a first half of line 23 of the television signal, namely, after a run-in and a start code, 4 static bits to indicate the aspect ratio, 1 static bit to indicate camera mode or film mode, 3 reserved bits, 3 static bits to indicate subtitle information, and 3 reserved bits. The expression "static bits" means that in each frame, the same bits are transmitted until a new situation occurs which necessitates a change of at least one of these bits.